This invention relates in general to container insulating devices. In particular, the invention relates to an improved flexible insulating wrapper for beverage containers and the like.
Numerous types of insulators are available for insulating beverage containers such as cans and bottles for soft drinks and beer. Many types have attempted and failed to provide a simple wrap-around device that can hold the container even during use without adding substantial bulk, and can be manufactured mainly from the insulating material itself without having to assemble several separate pieces. Examples of devices that fail to exhibit all the desired features are disclosed in U.S. Pat. Nos. 3,813,801 to Vander Schaaf, 4,344,303 to Kelly Jr., and U.S. Pat. No. 4,549,410 to Russel. These structures lack bottoms for keeping the container from falling out of the insulator, create a relatively bulky package in combination with the container, or use complex, multi-part assemblies usually containing expensive and rigid materials.
An insulating device that exhibits all the above mentioned features is described in U.S. Pat. No. 4,583,577 (hereafter the ""577 patent), issued to the inventor and incorporated herein by reference. The insulator has the advantages that it can be nested for shipping and storage, and that the insulated container can be placed within the type of supportive beverage holder typically available in cars, boats and other vehicles. Various other advantages and features of the design are enumerated in the ""577 patent.
The device disclosed in the ""577 patent has an sidewall part made from a strip of insulating material formed into a roll, and a bottom member made up of a plurality of bottom segments that provide support for the container and hold the container within the insulator. The ends of the sidewall strip are designed to overlap, allowing the effective radius of the sidewall to adjust automatically to conform to the container inserted within it. The bottom segments are substantially triangular in shape, and are designed to interleave like a camera iris. While this type of structure works with normal containers, experience has shown that the segments can sag when supporting a heavier than average container. Furthermore, the areas where the individual bottom segments join the sidewall strip weaken with repeated load cycles, so that the bottom segments sag still further and can even fail to hold the container inside the device during use. A structure that has greater strength and resistance to sagging, and that retains this strength and sagging resistance over many cycles, is therefore desired. Also, in many cases it is preferred that the bottom of the insulator lie flat on the supporting surface. This cannot be achieved with the ""577 structure due to the overlapping nature of the segments. A desirable structure could also cushion containers that are packaged collectively (for example, six-packs of glass bottles) to protect the containers from breakage that can occur during shipping and handling when the individual containers strike one another. The improved structure should retain the ""577 structure""s ability to form a snug, friction fit with the container, and automatically adjust to provide this fit over a range of container diameters, yet still allow a container to be inserted into and removed from the insulating cover with less force than existing structures. Finally, it is preferred that the improved structure be capable of being expanded and contracted without the individual elements of the device interfering with one another.
In general, a structure having the desired features and advantages has a sidewall member and an bottom member formed integrally from a single piece of insulating material. The sidewall member has ends that overlap when the device is in an unexpanded orientation, which is defined as the orientation of the device at rest without a container in the device. The sidewall member also forms a frusto-conical shell in the unexpanded orientation, to aid nesting of the devices within one another. The bottom member has an solid, continuous annular portion extending from the bottom edge of the sidewall member. In one embodiment, this annular portion alone is used to engage the bottom of the container, but the preferred embodiment includes a number of tabs extending from the annular portion toward the axis of the cylinder formed by the sidewall member. The tabs in this embodiment are designed to engage the bottom of the container rather than the annular portion. The tabs are spaced sufficiently far apart so that they do not overlap even when the cover is in the unexpanded orientation.
Additional features and advantages of the invention will become apparent in the following detailed description and in the drawings.